Polyhydric alcohol esters of phenoxyacetoxyacetic acid



Patented July 29, 1947 rotrnrnnrc ALCOHOLESTERS F PHENOXYACE'IOXYACETIC ACID Maurice Leon'Ernsberger and Paul Swithin Pinkney, Wilmington, Del., assignors to'E. I. du Pont de Nemours & Company, corporation of Delaware v No Drawing. Application Serial No. 495,770

2 Claims. 1

This invention relates to a new class of organic esters. More particularly, it relates to a specific type of organic esters particularlysuitable for use as cellulose derivative plasticizers.

Many plasticizers for organic estersv of cellulose are known, but'few meet either of two important requirements,'viz., compatibility at the high concentration required for good pliability, and satisto our knowledge, meets both requirements.

It is an object of this invention to provide a new class of organic esters.

ing properties as plasticizers for cellulose esters.

g A further object comprises cellulose ester com positions plasticized with the esters of this inesterified with an aryloxymonocarboxylic acid,

Another object is to provide a class of compounds possessing outstandfactory resistance to extraction by water. None,

- been removed, and the ester isthen steam dispreferably an aryloxy aliphatic monocarboxylic acid, and of cellulose ester compositions plasticized with these esters.

The invention is illustrated by the following examples describing the preparation and use of a representative member of the class, ethylene glycol bis-(phenoxyacetoxy) acetate, 9. compound having the formula The term parts" in the examples signifies parts by weight."

ErampleI A mixture of 124 parts of ethylene glycol (2 moles) and 362 parts of methyl glycolate (4 moles) is heated in the presence of 5 parts 01 litharge in a still fitted with an eflicient fractionating column to separate the methanol formed by ester interchange. The reaction mixture is heated first at atmospheric pressure and then at a pressure of 150 mm. of mercury until all the methanol formed in the reaction hasoeen removed. A pot temperature of 132-205" C. is used for the reaction at atmospheric pressure, and atemperature of 75-190 C. is used for the Portion of the reaction carried out at reduced pressure. The litharge is then filtered from the reaction mixture and to the filtrate is added 608 parts of phenoxyacetic acid (4 moles), 315 parts of ethylene dichloride, and 10 parts of p-toluenesulfonic' acid. This mixture is then heated at a Wilmington, {Del a July 22, 1943,

2 reaction temperature of 107l26 C. in a still fittea with an efiicient fractionating column until all the water formed inthe reaction has been.

removed. The. ethylene dichloride, which; serves ester is'heated in the presenceo20 parts of decolorizingcarbon at a temperature of 100 C./50 I mm, pressure until excess ethylene dichloride has tilled for 25 minutes at -100" C./350 mm. pressure.- The es'teris finally dried by further heating at 90-105 C./40 mm., and then filtered. The product, amounting to 708 parts, is a very viscous, amber colored liquid which solidified on standing at room temperature. It has a saponi fication number of 496. Calcd. for C22H22O1o sap. No.=502.

In place of ethylene glycol, any monomeric polyhydric alcohol may be used-including propylene glycol, butylene glycol, glycerol, erythritol, the distillable polyalkylene glycols, etc. Other monocarboxylic hydroxy acids, such as lactic acid, beta-hydroxypropionic acid, apha, beta and gamma hydroxybutyric acids. etc., in the form of their esters with voatile alcohols such as methanol, may be used in place of methyl glycolate. Suitable aryloxy monocarboxylic acids include alpha and beta-phenoxypropionic acids, the phenoxyand naphthoxybutyric acids, etc.

In addition to the preparative method described in the above example, which involves an ester interchange reaction, it is possible to prepare esters of this type by esterifying the hydroxy acid with the aliphatic polyhydric alcohol by usual esterification methods and then further esterifying the hydroxyl group of the hydroxy acid ester with the aryloxycarboxylic acid. Conversely, the hydroxy acid may first be esterified with the aryloxycarboxylic acid, and'the resulting acid used to esterify the polyhydric alcohol.

At least one of the hydroxy] groups of the polyhydric alcohol should be esterified. Preferably, all of them are esterified. i

The use of the esters of this invention in the plasticlzation of cellulose esters is shown in the following example.

Example II A solution of 12 parts of cellulose acetate 01 about 57% combined acetic acid content and 14.5 parts of ethylene glycol bis-phenoxyacetoxyacea v 3 tate'in '59 parts or acetone is prepared. A mm is cast by spreading thi solution on a suitable support and evaporating the solvent. After the film is substantially dry, it is seasoned for 8 hours at 55 C. The resulting film, 0.005" thick, loses only 0.8% oflts weight by immersion in water for 6 hours at 25 C. In comparison, a'fllm of the same type oi cellulose acetate plasticized with 50 parts of ethylene glycol bis-acetoxyacetate per 50 parts of cellulose acetate loses 24% 01' its weight on immersion in water for 6 hours at 25 C.

The plasticizers of this invention are of outstanding advantage for use with cellulose esters of organic acids particularly cellulose acetate but may also be employed with cellulose cluding mixed esters in general.

The use of ethylene glycol bis-phenoxyacetoxyacetate in cellulose acetate compositions suitable,

for use as photographic film base is illustrated by the following example:

H Ezample III 1 A film 0.005" thick is prepared by casting a esters, ill-.

, '1. Ethylene glycolibis-phenoxyacetoxyacetate.

solution or parts of cellulose acetate of 56% combinedacetic acid content, 5 parts of ethylene glycol bis-phenoxyacetoxyacetate, and 114 parts of acetone on a suitable support and removing the solvent by evaporation. 1 The resulting films have improved resistanceto water. in comparison with similar films plasticized with the commercially used triphenyl phosphate. The film Plasticized with glycol bis-phenoxyacetoxyacetate absorbs 2 only 3.9% water (average of amounts absorbed after25 and minutes immersion in water at 25 0.). Asimilar film plasticized with the same proportion of tri-phenyl phosphate hasa water 2. An ester of a distillable polyhydric alcohol or the class consisting of ethylene, propylene, and butylene glycols, glycerol, erythritol, and the distillable polyalkylene glycols in which all. the hydroxyl groups of the polyhydric alcohol are replaced by the radical of phenorwacetoxyacetic acid.

MAURICE LEON ERNSBERGER. PAUL SWITHIN PINKNEY.

REFERENCES CITED "The following references are of record in the tile of this patent:

I 'UNITED STATES PATENTS Number Name Date 2,142,126 Grether Jan. 3, 1939 2,170,996 Grether Aug, 29, 1937 2,234,706 Normington et a1. Mar. 11, 1941 1,808,998 Sheppard ct al June 9, 1931 1,929,290 Schmidt Oct. 3, 1933 2,170,995 Grether et a1. Aug. 29, 1939 Carruthers et al. May 16, 1939' 

